Bowling ball thumb-hole duplication jig and methods of use

Abstract

An apparatus and methods for duplicating a thumb-hole of an original bowling ball into another bowling ball are disclosed. The preferred apparatus includes a bowling ball thum-bhole duplication jig for holding an original bowling ball during the casting of a flexible mold of a thumb-hole of the ball. A preferred method employs components of the jig and the flexible mold in the making of a slug for insertion into a radial slug receiving bore of another bowling ball.

I claim:  
     
         1 . A bowling ball thumb-hole duplication jig comprising: 
 a jig base having a vertical jig base bore, two bridge supports mounted to said base, said supports depend upwardly from said base, said supports equally spaced from said vertical jig base bore, said supports attached to a clamping bridge, said clamping bridge having a lower bridge bore, and a tube received into and seated in said lower bridge bore.    
     
     
         2 . A bowling ball thumb-hole duplication jig according to  claim 1  wherein said lower bridge bore partially extends into said bridge perpendicularly from its lower surface, said lower bridge bore being coaxial with an upper bridge bore, said lower bridge bore having a larger diameter than said upper bridge bore, said upper bridge bore extends fully through said bridge perpendicularly from its top surface.  
     
     
         3 . A bowling ball thumb-hole duplication jig according to  claim 1  wherein said tube having a chamfered outer end.  
     
     
         4 . A bowling ball thumb-hole duplication jig according to  claim 2  wherein said tube having a chamfered outer end.  
     
     
         5 . A bowling ball thumb-hole duplication jig according to  claim 2  wherein said upper bridge bore having the same diameter as the inside diameter of said tube.  
     
     
         6 . A bowling ball thumb-hole duplication jig according to  claim 1  wherein said tube having a tube registration marking.  
     
     
         7 . A bowling ball thumb-hole duplication jig according to  claim 2  wherein said tube having a tube registration marking.  
     
     
         8 . A bowling ball thumb-hole duplication jig comprising: 
 a clamping bridge, said clamping bridge having a centered lower bridge bore, said lower bridge bore partially extending into said bridge perpendicularly from its lower surface, said lower bridge bore being coaxial with and having a larger diameter than an upper bridge bore, said upper bridge bore extending fully through said bridge perpendicularly from its top surface, a pipe coaxially received into and seated in said lower bridge bore, said bridge having two bridge support slots, one at each end, each of said slots respectively receiving a bridge support and cooperating with said support, a washer, and a wing nut to secure said bridge to a jig base.    
     
     
         9 . A bowling ball thumb-hole duplication jig according to  claim 6  wherein said tube has a chamfered outer end.  
     
     
         10 . A bowling ball thumb-hole duplication jig according to  claim 6  wherein said upper bridge bore having the same diameter as the inside diameter of said tube.  
     
     
         11 . A method for duplicating a thumb-hole from an original bowling ball into another bowling ball, said method comprising the steps of: 
 a. providing an original bowling ball having a thumb-hole; said ball having a marking on its surface showing a y-axis of the grip;    b. providing a bowling ball thumb-hole duplication jig having a jig base having a vertical jig base bore, two bridge supports mounted to said base, said supports depend upwardly from said base, said supports equally spaced from said vertical jig base bore, said supports attached to a clamping bridge, said clamping bridge having a lower bridge bore, said lower bridge bore partially extends into said bridge perpendicularly from its lower surface, said lower bridge bore being coaxial with an upper bridge bore, said lower bridge bore having a larger diameter than said upper bridge bore, said upper bridge bore extends fully through said bridge perpendicularly from its top surface, a tube received into and seated in said lower bridge bore, said tube having a chamfered outer end, and said tube having a tube registration marking on its outer circumference at said chamfered outer end;    c. placing said ball in said jig base bore;    d. centering said thumb-hole in said jig;    e. assembling said jig around said ball with said chamfered outer end evenly resting on and closely abutting said ball and encircling said thumb-hole, said tube aligned radial to the center of said ball, and said tube registration marking aligned with said y-axis of the grip;    f. tightening said jig around said ball;    g. casting a mold by pouring a mold material down through said upper bridge bore to fully fill said thumb-hole and partially fill said tube;    h. after said mold is cured, removing said clamping bridge and said tube from said jig;    i. marking said mold with a mold registration mark to index said mold to said yaxis of the grip at the point where said y-axis of the grip meets said mold;    j. removing said mold from said thumb-hole, said mold having a bottom end;    k. mounting said mold in said upper bridge bore with said bottom end extending vertically upward through said lower bridge bore and into said tube, said tube seated in said lower bridge bore;    l. casting a slug by pouring a slug casting material into said tube to surround said mold to a suitable depth;    m. after said slug is cured, removing said slug and said mold from said bridge and said tube;    n. marking said slug with a slug registration mark aligned with said mold registration mark to index said slug to said mold and said mold registration mark;    o. providing a second bowling ball having a y-axis of the new grip marked thereon;    p. making a radial slug receiving bore in said second bowling ball;    q. applying an adhesive to a portion of said receiving bore; and    r. inserting said slug intd said slug receiving bore with said slug registration mark aligned with said y-axis of the new grip.    
     
     
         12 . A method for duplicating a thumb-hole from an original bowling ball into another bowling ball according to  claim 11  wherein said radial slug receiving bore is centered on said y-axis of the new grip.  
     
     
         13 . A method for duplicating a thumb-hole from an original bowling ball into another bowling ball according to  claim 11  said method further comprising the steps of: 
 a. spraying the insides of said tube and said thumb-hole with a mold release spray before said jig is assembled and tightened around said ball; and  
 b. spraying the inside of said tube and said mold open to the environment inside said tube with a mold release spray before said casting material is poured into said tube.